Crossveinless-c, the Drosophila homolog of tumor suppressor DLC1, regulates directional elongation of dendritic branches via down-regulating Rho1 activity.

Laboratory of Cell Recognition and Pattern Formation, Graduate School of Biostudies, South Campus Research Building (Building G), Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8507, Japan.
Genes to Cells (Impact Factor: 2.73). 04/2010; 15(5):485-500. DOI: 10.1111/j.1365-2443.2010.01399.x
Source: PubMed

ABSTRACT Diverse neuronal subtypes develop distinctive morphologies of dendritic arbors that receive synaptic or sensory inputs. Dendritic arbors of many subtypes take on a polarized shape, and one underlying mechanism is unidirectionally biased elongation of dendritic branches. As reported herein, we found that Drosophila Crossveinless-c (Cv-c) was a key regulator for such directional growth. In the cv-c mutant, two subclass of multidendritic sensory neurons examined formed dorsally directed branches; however, dendritic branches had difficulty in growing along the anterior-posterior (A-P) body axis. Cv-c belongs to the family of Rho GTPase-activating proteins (RhoGAPs) and is the homolog of human tumor suppressor DLC1. The RhoGAP activity of Cv-c was required cell-autonomously for the A-P-oriented growth, and Cv-c elevated the GTPase activity of Rho1 and Cdc42 in a cell-free assay. Our analysis of genetic interactions suggested that Rho1 was the target of Cv-c in vivo. All of our results suggest that Cv-c contributes to sprouting and subsequent growth of the A-P-oriented branches through negative regulation of Rho1. We discuss a role of Cv-c in dendritic growth in response to environmental cues.

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